Page:Popular Science Monthly Volume 44.djvu/436

424 with which legend declared that it attracted its sympathizing victims to the bank of the stream, are highly decorative, if not beautiful. The head, narrow and flat, resembles the head of a snake; the nose is sharp, and the fixed and motionless eyes are of the palest dusty gold, set in a short, horny pillar of a deeper golden brown. The crocodile's coat of armor is less complete than that of the alligator, and its quick, vivacious movements make it far more troublesome to the keepers when the tank has to be refilled and cleaned than the big alligators, which will allow themselves to be used as stepping-stones as the water ebbs away. "The heloderm, a fat and torpid lizard from Arizona, is supposed to be the sole existing member of its tribe, which possesses not only the poison glands that exist in most of the toads, but also the true poison teeth, with a channel for the emission of the venom. The lizard is about a foot and a half long, with a fat, fleshy body, a round tail ending in a blunt point, and a flat head with squared sides, resembling a small padlock. The whole body is covered with a curious coat of scales, like black and pink beads, arranged in an arabesque pattern. In its daily life it is a dull and stupid creature, feeding mainly on eggs, which it breaks and laps with its tongue. Its first and only victim was a guinea-pig that was put into its cage with a view to testing the reports as to its poisonous nature, which were by no means universally credited. The lizard bit the guinea-pig in the leg, and the animal died in a minute and a half, almost as soon as after the bite of a cobra."

Fresh Air for Legislators.—The Speaker of the British House of Commons recently pointed out a great need of the house over which he presides, and of other legislative bodies as well. Having arrived at Leamington for a little rest, he expressed his pleasure at finding himself there, "under the open air of heaven," after scenes of great anxiety and responsibility. There are very few men, as the Lancet remarks, commenting on this observation, having business of their own to attend to who can stand the work of Parliament from three in the afternoon till twelve at night without breaking down. The air of the house—whatever the "scientific ventilation"—is not the "open air of heaven." In addition to the want of air and want of space, are the temperature of discussion and the tension of highly strung men greatly differing in opinion. The Speaker is quoted as saying that the deterioration of members in health is evident from day to day, and that he sees men gradually becoming degenerate. He has been told by a cabinet minister, who is a peer, that he can recognize members of the House of Commons "by their pallid countenances," and can distinguish between them and members of the House of Lords. "It is the height of unreason to expect good legislation under such absurd conditions."

Requisites of a Flying Machine.—The principle seems to be accepted now by most of the students of aërial navigation that the successful air vessel, instead of a balloon, must be a body heavier than the air, and must be sustained as well as propelled in some way similar to that by which a bird flies. This principle was fully set forth in The Popular Science Monthly for January, 1892, by M. G. Trouvé, whose aviator, therein described, had wings acting almost precisely like those of a bird. M. Trouvé proposed for his machine an ingenious motor, which was to be actuated by the alternate compression and expansion of a gas in a Bourdon tube. Previous to M. Trouvé's paper, articles setting forth the principle of "heavier than the air" had been published by Mr. O. Chanute, Prof. S. P. Langley, and Mr. H. S. Maxim, and several have been published since in American magazines and journals. A writer who discusses the subject of aërial navigation in the Boston Herald raises the objection to a wing-motion, such as M. Trouvé's aviator contemplates, that the power needed to secure the velocity which an oscillating machine would require would probably cause the machine to destroy itself by the violence of its own vibrations. He proposes instead to depend on an aëroplane to hold the machine in the air, and to use a screw propeller as a source of motive power. He would pattern and proportion the aëroplane after the position of the motionless wings of a loon in scaling descent, as after they have been paralyzed by a shot hitting the brain; place the screw in front, on the principle that an arrow can not fly except with its heavier end foremost, and